“…Diacetoxy-diphenyl-pyridyl-methane and dihydroxydi phenylisatin reduce, in vitro and in vivo, the active transport of sodium and water in the small intestine of the rat by inhibition of the "sodium pump" (122). Inhibition is even more intense in the colon contributing essentially to the laxative properties of these compounds (123)(124)(125). A certain independ ence exists between the absorption of sodium and water, with evidence of a greater retention of sodium, possibly related to water elimination into the lumen of the colon.…”